Journal of Computer Applications

On next generation network and next generation Internet

Hua-sen ZENG

2007, 27(11): 2615-2618.

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Comprehensive review and analysis of international research and standardization activities pertinent to Next Generation Networks (NGN) and Next Generation Internet (NGI) were provided. A strategy in developing NGI architecture was proposed based on the experience gained in development of Single physical layer Userdata transfer & switching Platform Architecture (SUPA). A brief discussion on SUPA and Ethernetoriented Physical Frame Timeslot Switching (EPFTS) was given, and how to solve QoS provisioning, highperformance switching and Internet security by using the techniques was also discussed.

Progress of NGN standardization in telecommunication community

Hui-ling ZHAO

2007, 27(11): 2619-2622.

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Comprehensive review and analysis of the standardization process on Next Generation Network (NGN) from the point of view of telecommunication community were made. It covered the concept and connotation of NGN, NGN standardization process, and future development. An emphasis had been given to techniques such as softswitching, IP Multimedia Subsystem (IMS), and MPLSbased IP carrier backbone networks. Finally, the author pointed out: Internet technologies had provided challenges as well as opportunities for common carriers in the long run; matured techniques, especially those with high performance/price ratio would dominate the future.

Ground traffic simulation based on general trigger system

Lei HE Pan-liang GUAN

2007, 27(11): 2623-2625.

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The problems encountered in ground traffic simulation were analyzed, a multiAgent system with vehicles and virtual trafficpolices as intelligent Agents was constructed, and then the communication and consistency problems with general trigger system model among multiple Agents were resolved. The change of information quantity caused by induction of virtual trafficpolice and general trigger system model was also analyzed quantitatively. The method and idea described in this paper are proved efficiently by an experimental model of ground traffic.

Research and design of ground-delay policy model based on discrete event system

Nan Guo Zhi-shu Li Zhuo-yang Song

2007, 27(11): 2626-2629.

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A GroundDelay Policy (GDP)model with its algorithm with constrained airpor's arriving capacity was analyzed and modified. Different from conventional models, the Discrete Event System (DES) method was adopted to analyze the air traffic flow management. The simulation result shows that compared with the conventional GDP model based on linear planning, the GDP model and algorithm with constrained airport's arriving capacity can not only solve the continuity of flight time efficiently, enhance the precision of optimized arriving time, but also reduce the complexity of total calculation significantly.

Improved NS cellular automaton model for simulating traffic flows of one-lane

2007, 27(11): 2630-2631.

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We improved the Nagel-Schreckenberg (NS) cellular automaton model for onelane traffic flows. A cellular of NS model was divided into two, so did the time step. On the other hand, that the acceleration ability of a stock-still car was weaker than that of the running one was considered. Furthermore, the relationship between randomization deceleration probability and the traffic density was taken into account. By computer simulations, some basic qualitative results and the fundamental diagram of the proposed model were obtained. Compared with other models, the fundamental diagram of the proposed model is more realistic. 〖MZ）〗〖BP（〗英文关键词〖BP）〗

Research into distance influence of harbor-shaped bus stop based on cellular automaton

WANG Hai-long QIAN Yong-Sheng

2007, 27(11): 2632-2633.

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The impact on urban traffic flow of public transit system is very prominent. Based on some cellular automaton (CA) models of traffic flow, a new traffic CA model with mixed traffic flow, which considered the public transport vehicle and harbor-shaped bus stop in twolane, was proposed. It calibrated the parameters such as length of the cellar automaton, operation speed, and random slow mechanism. And it not only set up bus station and improved vehicle changing lane regulation, but also limited maximal velocities to different vehicle types and advised that they occupied different number of cells at every time step. Some simulations were carried out and the results show that this model reproduced the relationship among three parameters of traditional traffic flow, which paved the way for studying mixed traffic flow in detail.

Research of traffic application based on travel time detection system

2007, 27(11): 2634-2636.

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With the improvement of travel time detection algorithm, it is widely used in traffic research. A travel time detection system was introduced based on the precise vehicle plate recognition technology, and the analysis and process of detected data were mainly expatiated. A new short-term traffic flow prediction model was proposed, which was an expansion of cellular automaton model with travel time as critical target parameter. Its key technology and difficulty were discussed and analyzed.

4-D trajectory prediction model based on data mining

2007, 27(11): 2637-2639.

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Due to the large errors of traditional aerodynamic 4-D trajectory prediction models, a prediction model based on mining flight history data was proposed. Firstly, the factors that had impact on total flying time were found out from flying history, and the flying time of next flight was predicted. Then from the flying position data, the positions where aircraft was located in each sampling period were worked out, and the whole prediction 4-D trajectory was got. Simulation tests prove the accuracy and availability of this model.

Urban loop-road traffic-coordination-control system based on TWP-PSO

Chang-xi MA Yong-sheng QIAN Chun-lei WANG

2007, 27(11): 2640-2642.

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According to the loop characteristic of urban road network in some areas of our country, an urban looproad traffic-coordination-control system based on two-way parallel particle swarm optimization (TWP-PSO) was proposed. In this system, the control sub-area was closed loop road in road network, a three-level stepped distributed construction and the TWP-PSO algorithm were adopted, and the cycle，offsets and splits were optimized hierarchically, then the preset scheme was formed by cooperative controlling for different closed loops. The final signal control project was determined by judgment and choice from surface controlling rate of system hypothesis. The result indicates that the control system can reduce delay and the stopping rate effectively in the region.

Model and calculation for tracking interval control of high-speed passenger trains

2007, 27(11): 2643-2645.

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We analyzed the types of the train tracking interval and running process of high-speed passenger trains, and constructed the models for section tracking interval and station tracking interval in the signal systems of high-speed passenger trains. Different calculating methods for the corresponding train tracking intervals were deduced accordingly and verified with Matlab, and the calculation results were analyzed.

Dispatching and controlling system of enterprise railway based on workflow model

2007, 27(11): 2646-2648.

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According to the characteristics of the enterprise railway, an integration scheme of dispatching and controlling was designed. In order to coordinate the sub-systems, the scheme worked on workflow technique to realize the automation of the working process. To solve the problems in modeling the system with the standard workflow net, standard workflow model was expanded. In the expanded model, the color was used to describe information flowing in workflow net, and the compounded color identifier variable was used to represent the individuals. The expanded model has better structure, better abstracting capability and extensive description capability.

Automatic train operation and its control algorithm based on CBTC

Changqian Zhu

2007, 27(11): 2649-2651.

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Communication Based Train Control (CBTC) is the trend of the Automatic Train Control (ATC) technology. The basic structure and functions of the CBTC based ATC system were introduced. Traditional control methods can not satisfy the no linearity and time variety of the train operation parameters. Artificial intelligent control theory is a better solution. And then the automatic train operation algorithms of the modern control theory such as Automatic Train Operation (ATO) systems based on expert system, fuzzy control and fuzzy neural networks were modeled and described.

Virtual node: improvement of work load balance in peer-to-peer system

Da-lu ZHANG Ping XU

2007, 27(11): 2652-2655.

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Ability difference of P2P nodes causes the work load imbalance which always swaps between nodes. To address this problem, the concept of virtual node was originally presented that the nodes were transferred into logical nodes with similar abilities, by dividing and aggregating the nodes. Virtual node can eliminate the ability difference at best effort, achieve load balance, and increase performance and efficiency.

Research of QoS hierarchical adaptive tactic based on mobile Internet

Jian－Sheng XUE

2007, 27(11): 2656-2658.

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The QoS hierarchical adaptive tactic based on real-time emergent management was proposed, using the method of hierarchical mapping table to establish the QoS mapping relationship between mobile network and Internet. And the selecting algorithm on QoS of multi-operation and aggregation stream was put forward as well, using the gateway linked to Internet as the decision-making node of adaptive QoS modulating. The gateway supervised the change of network load. According to the operation stream QoS was modulated timely which made decision timelier. The simulation results show that the tactic solves the problem of the match-mapping between mobile network and operation QoS which Internet provides, reduces the transportation delay over 20%, and restrains the users from enlarging their needs blindly and avoids the aggravation of the network burden caused by the users attack viciously.

Analysis and depiction of network traffic based on wavelet technique

Jun Hu Xian-hai Tan Yu-fei Qin

2007, 27(11): 2659-2661.

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Many research studies have proposed scaling of real network traffic has a notable effect on the network performance: the self-similar phenomena over large scale, the multi-fractal phenomena over small scale. As multi-fractal providing the upstanding frame of mathematics to depict the singularity of traffic over small scale, and the wavelet transform taking effect on un-correlation to the traffic which is long range dependent, it is necessary to research the multifractal model based on wavelet technique. The multi-scale provides the new method to study the characteristics of traffic. In order to depict the characteristics of modern network, the real traffic based on the wavelet technique was analyzed, and the global characteristics and local characteristics of traffic were judged at first. Then, the traffic was divided into blocks, and the traffic between inner block and outer block was mixed. At last, when studying the factors which have impact of the multifractal on the traffic, it is found that, the mean and variance have impact of multifractal on the traffic.

A Transparency Dynamic Feed-back Load Balancing Algorithm Based on Cluster System

2007, 27(11): 2662-2665.

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With the broadly adoption of server cluster systems in the enterprise information system, the traditional algorithm of load balancing can’t satisfy the requirement of enterprise use because of either the expensive hardware cost or the limitation of algorithm itself. In this paper, a cluster based transparency dynamic feed-back load balancing algorithm (TDLBA) is presented. To simplify the distribution of the load balancer, improve the throughput rate and response time of the system, this algorithm not only considers multi-resources abundantly (such as CPU、memory、I/O and network bandwidths etc.), uses redundant backup strategy, adopts the dynamic feed back algorithm of the server nodes, but also brings in a redundant load node for the adjustment of load allocation. Conclusions can be drawn through test that this algorithm improves the service capability of the system effectively compared with static allocation algorithm.

Connectedness Assurance of Self-organizing Network Evolving

Xiao SUN Hui Wang Hao Wang

2007, 27(11): 2666-2668.

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The connectedness of network is important to the communication of network. This paper lists two basic modes of connection breaking in evolving process of self-organizing network, analyses the key factor and proposes a simple and convenient links replacement algorithm based on local connected domain optimization, which can assure the connectedness in evolving processes of network. Furthermore, simulation is used to verify the validity of algorithm and to discuss the related parameters and performance metrics of the algorithm.

Study on routing metric and accurate measurement of link quality in wireless mesh network

2007, 27(11): 2669-2671.

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The routing technology based on Ad Hoc was introduced into Wireless Mesh Network (WMN) as the default routing standard described in IEEE 802.11s. But the backbone of WMN is different from Ad Hoc, the topology of WMN is more static than that of Ad Hoc. MRLQSR developed for relatively static WMN, combining the LQSR and WCETT, shows the better performance for WMN than pure routing of Ad Hoc. WCETT is the link-quality metric. An efficient and accurate measurement (EAR) for wireless link-quality was proposed. Accurate link-quality measurement is essential to the routing performance associated with link-quality-awareness routing protocol in WMN. The link-quality factors, such as link bandwidth and loss rate were discussed, and the utilization of link capacity improved by EAR was evaluated. The simulation results show that ETT and ETX with EAR significantly outperform original ETT&ETX with BAP.

Improved DV-Hop localization algorithm for wireless sensor networks

XiaoLong Zhang HuiYing Xie XiaoJian Zhao

2007, 27(11): 2672-2674.

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To overcome the disadvantage of DV-Hop algorithm when it was used to compute the distance of unknown nodes and beacon nodes in the wireless sensor network, an improved algorithm was proposed. In this improved algorithm, the distance of unknown nodes and beacon nodes was computed, using the angle ∠ABC formed by three neighbor nodes A, B and C in the path of unknown nodes and beacon nodes, and given distance data among the nodes. This angle ∠ABC was estimated with an overlapping degree of Bs neighbor node sets collecting with A and C, respectively. The experimental results show that the improved algorithm has more accurate locating compared with DV-Hop algorithm.

Simulation and performance analysis of link-quality aware AODV routing protocol

Lu Yang LU

2007, 27(11): 2675-2679.

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Ad Hoc On-demand Distance Vector (AODV) routing protocol selects the shortestpath or minimum hop count from source to destination as route selection metric. A new route selection metric was proposed in Linkquality Aware AODV (LA_AODV). It took route layer and physical layer into account. LA_AODV was introduced, and then the method of simulating LA_AODV in NS2 was expatiated. Some key problems were discussed. The simulation results show that LA_AODV protocol introduces much lower routing overhead while still providing better performance than AODV protocol in terms of throughput,cost and delay.

Assisting delivery model for peer-to-peer live streaming media based on artificial social-network

Liang-Jin Lu Xian-Hua Xu

2007, 27(11): 2680-2682.

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The problems of the existing P2P streaming models were analyzed. An inter-channel assisting delivery model was proposed. It extended the scope of cooperation from one program to the global overlay, and maintained persistent trust and cooperation relationship between peers by the artificial social network. It made full use of the free bandwidth to improve the play fluency by active assistance and passive assistance. A Tit-for-Tat mechanism was introduced to stimulate peers to help each other. The simulation results show that it can improve the QoS efficiently.

Research and design of P2P network hierarchical model SHDN

YUAN Fu-Cheng LI Zhi-Huai Zhou Xiao-Wei

2007, 27(11): 2683-2685.

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After the characteristics of the mainstream P2P network models were analyzed, a new hierarchical P2P network model called SHDN (Supernode based Hierarchical DHT Network) was designed. It features load balance, extensibility, dynamic character and higher efficiency. SHDN can offer the basal information services such as precise location of the users, administration by clusters, files transmission and so on. The design of the SHDN network model was described, and the rationality and the routing efficiency of SHDN were tested by emulation.

Motivation model for online public opinion based on cellular automata

2007, 27(11): 2686-2688.

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The online public opinion is a complex system. In order to study its propagation process and evolution tendency, a motivation model based on cellular automata for online public opinion was built. It could be used to simulate the change of individual free press number and the change of individual viewpoint in networks. In this model, individuals in networks were abstracted as cellulars. The tendency degree of a person's sensibility and the limit of this degree were used to confirm the state of cellular. The sensibility motivation was used to describe the movement rule of cellular. The change of individual number and the influence of the society paroxysmal events on the propagation of online public opinion were also considered. So the model could simulate the real events in networks well and truly.

Attack model based on both-branch fuzzy decision-making and fuzzy Petri net

Da-yong REN

2007, 27(11): 2689-2693.

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Based on both-branch fuzzy decision-making and fuzzy Petri net (FPN), a new network attack model named both-branch fuzzy Petri-net attack net (BBFPAN) is put forward; the aggressive and suppression factors to network attack are analyzed in this attack model. Based on this model, a reasoning algorithm is proposed, and the effectiveness of the algorithm is verified by experiment. This paper originally considers together the factors pro-and-con that have effect on attack so that a closer network attack description to reality is made by this model.

IP traceback based on unrepeatable packet marking scheme

2007, 27(11): 2694-2695.

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Defending against distributed denial of service attacks is one of the hardest security problems on Internet today. Based on the probabilistic packet marking scheme, a new unrepeatable probabilistic packet marking scheme was proposed and the adaptive strategy was applied to analyze marking probability. The results show that the scheme can effectively reduce the number of the packets needed for path reconstruction and the marking workload of routers, thus this scheme improves the efficiency of path reconstruction.

Online tracing Petri dish of large scale worm

Qiang LI Jian KANG Yang XIANG

2007, 27(11): 2696-2698.

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Breaking out of network worms brings a tremendous damage to the Internet. Launch the worm defense and response can improve network anti-strike capability. Tracing worm propagation path after its outbreak can reconstruct not only the earliest infected nodes but also the timing order of victims been infected. For the detection and defense of large scale Internet worm outbreaks, a convenient and safety experimental environment that capable of running real worm become an important work to observe large scale worm infection, intrusion and propagation, it can be a large scale worm testbed for forensic evidence. This paper presents a large-scale worm propagation experiments environment for tracing algorithm, which is an isolation environment that can run related experiments. To conform as much as really to the actual network, the experimental environment use virtual machine technology, simulate a large number of hosts and network equipments attend. According to the actual worm, this environment can trigger large-scale worm outbreaks within the controllable scope of human, observe propagation process of the worm, experiment detection and defense techniques, discover worm propagation characteristic such as scanning method and propagation process, real-time collect network traffic and propagation process, investigate network traffic, launch speculate algorithm for reconstructing out patient zero and propagation path of the worm. Then actual worm propagation process can be captured and compared with the results using tracing algorithm.

Design and implementation of multi-policy security model for Nutos operating system

XIA Lei HUANG Hao Shuying YU Zhiqiang WANG

2007, 27(11): 2699-2703.

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Increasing diversity and complexity of the computing environments result in various security requirements. MLS security policy only aims at confidentiality assurance, in less consideration of integrity assurance and weakness in channel control. To handle that the trusted subjects have many security shortcomings of MLS model, a multipolicy views security model (MPVSM) was presented. Based on the MLS model, MPVSM combined the domain and type attributes to the model, to enforce the channel control policy, make permission management more finegrained and enhance the ability to confine the permission of the trusted subjects. MPVSM was also able to enforce multipolicy views in operating system in a flexible way. The implementation of the MPVSM model in our prototype trusted operating system Nutos was also introduced.

Intrusion response based on SVM cost-sensitive decision model

Yu GUO

2007, 27(11): 2704-2706.

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Traditional intrusion detection model only considers attack damage and response cost. In this study, two important factors in decision process, the property value of attack target and the response risk were added, and the calculation methods with each cost were analyzed. Moreover, a method for assessing attack target as the immaterial asset was proposed and the process that adopted support vector machine (SVM) model to set up the analysis model of the cost decision was described in detail. At last, according to the daily record, the experimental results show that the decision result of this model has higher accuracy.

Pseudonym-based signature scheme for anonymous communication in wireless Ad Hoc networks

Si-Sheng CHEN Li XU Zhi-de CHEN

2007, 27(11): 2707-2709.

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In order to hide the identities in anonymous communication in Ad Hoc networks, the nodes use the pseudonyms to replace the real identities of the nodes. A pseudonymbased signature scheme from bilinear pairing was proposed for anonymous communication in Ad Hoc networks. The new scheme can solve the problem: the anonymous communication is not blind to Private Key Generator (PKG) and the PKG can forge the nodes signature using the pairingbased signature scheme in the anonymous communication. At last, the correctness, pseudonym and security of the new scheme were analyzed.

Research of trust evolutionary mechanism based on game theory in P2P networks

Man Hong-Fang 满红芳

2007, 27(11): 2710-2711.

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The evolutionary tendency of trust relationship among peers was analyzed with the replication dynamic mechanism based on the game theory. The trust relationship between peers will be the longterm tendency of evolutionary adjusted by the receipts mechanism in the replication dynamic proceeding of evolutionary game. The simulation results show that the trust will be the stable strategy of peers with appropriate mechanism, and then the security and stability of network will be enhanced.

Real-time updating model of access control policies and its implementation

Yan Li Hong-Wei Zhu

2007, 27(11): 2712-2714.

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Dynamic environments pose new challenges to access control. In order to guarantee the security of information system in dynamic environment, the needs for realtime update of access control policies rise while the policies are in effect and enforcing the changes immediately. Simple concurrent control algorithms for realtime update of access control policy were given in the model. The model and algorithms are useful for concurrent environment in which multiple subjects access and modify data and access control policies, while the policies are in effect.

Proxy blind signature based on identity

DU Huan-Qiang

2007, 27(11): 2715-2717.

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Making use of bilinear map and the ideas of identity-based signature, a new efficient identity-based proxy blind signature was proposed. The scheme combined the advantages of proxy signature and blind signature. It could prevent the original signer from generating proxy blind signature and the signer cannot make a linkage between the blind signature and the identity of the requester. Furthermore, its efficiency and security are also better than the existing ones.

New proxy blind multi-signature scheme

Zhen-peng Hu Hai-feng Qian Zhi-bin Li

2007, 27(11): 2718-2721.

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With proxy multisignature, many original signers can delegate their signing power to a proxy signer in such a way that the proxy signer can sign any message on behalf of them. In blind signature, the signer cannot make a linkage between the blind signature and the identity of the requester. Therefore, they are easily applied in electronic commerce. Based on Schnorr signature scheme, a new proxy blind multisignature scheme was proposed. One proxy signer can generate a proxy blind multisignature on behalf of many original signers. This scheme satisfies the security properties of both the blind signature scheme and the proxy multisignature scheme. It has advantages such as low computation load, high efficiency and security, and that the length of signature does not increase when the new original signers join in.

Improved route protocol of security mobile Agents

Zhoujian Zhou Benda

2007, 27(11): 2722-2724.

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The security mobile Agent protocol based on Merkle tree was analyzed, which had large computation overhead and high cost. Therefore, a secure itinerary protection of mobile Agents based on Hash function was proposed. The analyses show that the improved protocol can keep its security and computation cost only to 1/2 overhead, which is of high application value.

Dynamic composition of Web service workflow based on semantic description

2007, 27(11): 2725-2727.

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Traditional static workflow is hard to get adapted to dynamic, flexible modern business process. In recent years, Web services technology has been developing. It not only makes the activity in workflow by Web services form, but also workflow itself is invoked by Web services, especially semantic web services technology is developing, which makes it possible to compose automatic Web service workflow. A model of semi-structure workflow ontology based on ontology theory was proposed, and a WFMS based on agent technology using the mentioned model of semi-structure workflow ontology was designed.

Code-on-demand migration in wireless migrating workflow environment

Wang Hong

2007, 27(11): 2728-2732.

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In order to support largescale migrating workflow program running on resourcelimited mobile devices, a model called codeondemand migration in wireless migrating workflow environment was introduced. Firstly the concept of the workflow unit was given, which was the basis for the codeondemand migration in wireless migrating workflow environment. Then some critical problems in the integrated architecture of the model were discussed, such as the structure of the dock server and the migrating workflow management server. At last, the model was implemented. The experiment indicates that the model is reasonable and its implementation is reliable. It effectively supports the application of the migrating workflow in the wireless environment.

Discussion of BPEL4WS-based Web service integration

2007, 27(11): 2733-2735.

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Business Process Execution Language for Web Services (BPEL4WS) is the standard for Web service integration. Its function is to assemble a serial existing Web services to form a new Web service. Based on the basic conception concerning business process and workflow, a Web service integration modeling was proposed, and then a common Web service integration method and procedure were put forward. By means of the method and the procedure, a demonstration was brought forward to illustrate its practicability in Web service integration.

Primitive-based approach of user interface design pattern modeling

2007, 27(11): 2736-2739.

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To improve the efficiency of user interface development, pattern-based user interface patterns in terms of the composition of user interface were proposed. Pattern primitives were elicited to describe the user interface patterns formally from different aspects. Furthermore, based on the user interface patterns and the pattern primitives, a primitive-based approach of user interface design pattern modeling was presented. Enough information of user interface display unit could be got from the customized pattern primitives to implement the user interface pattern modeling and guide the code generation process.

Schedule mechanism of TinyOS and its real-time schedule component design

Kuian LIU

2007, 27(11): 2740-2742.

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TinyOS is an opensource component operating system for sensor networks nodes that has very limited resources. TinyOS was implemented in component-developing language nesC. Through analyzing the schedule mechanism of TinyOS-2.x, a soft real-time scheduler component was designed and implemented for realtime applications. Simulation results in TOSSIM demonstrate that the soft real-time component improves the real-time performance of TinyOS.

Dynamic evolution method for embedded systems

Lei Deng Jian Wu

2007, 27(11): 2743-2746.

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Concerning the dynamic evolution and QoS requirement problems of embedded application systems, an embedded component model - ESIM model was outlined. The dynamic evolution method of the ESIM model was discussed, including the evolution strategy and process, and the discussion stressed the check of the dynamic evolution request according to the QoS layer contract, the evolution contract and the resource consumption information. Simulation results show that the dynamic evolution system of the ESIM is better for solving the state transmission, resources occupation and realtime ability problems, as the duration and resource consumption of the evolution are predictable.

Compression and application of transition probability matrix in Markov prediction model

2007, 27(11): 2746-2749.

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Markov prediction model is the base for Web prefetching and personalized recommendation technique. The existence of a large amount of Web objects results in a large increase of the number of states which represent the users visit transfer behavior, which also causes the issue of huge spatial complexity in prediction model. Based on the Web site Link Structure (WLS), in view of the transition probability matrix in Markov prediction model, a measurement method based on row similarity and column similarity was proposed. Firstly, the similar matrix was calculated. Then the row similarity and column similarity were used to obtain similar pages simultaneously which could be compressed together. Thus the number of states could be reduced. The experimental results show that this model have good overall performance and compression effect, and keep relatively higher prediction accuracy and recall in terms of the efficiency of Web prefetching.

Replica location strategies in data grid based on Globus platform

Tian-Lai LI Fang-Ai LIU

2007, 27(11): 2750-2752.

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In the Internet environment, the data grid is divided into several storage subregions. Based on Globus platform, a threelevel structure of replica location and the Replica Location Algorithm Based On Giggle (RLABOG) were proposed. Discussion indicates that the new strategy reduces the access time and improves the system performance.

Data storage method of 3D model on military simulation entities

Hong YIN Ji-Heng XU Wei YE

2007, 27(11): 2753-2755.

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To improve the data storage performance and utility efficiency of 3D model on military simulation entities, categories of the models were proposed. Rules of 3D models on level of details, grade of damage, texture and grouping were constituted. Data storage framework for 3D model, hierarchical architecture of the models, and data structures for each level architecture were constructed. Finally, the algorithm for reconstructing 3D models was introduced.

Study on join query processing schemes in a mobile computing environment

Min WANG Yu-quan ZHU Chun-fen ZHANG

2007, 27(11): 2756-2759.

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Under a mobile computing environment, it can reduce both the amounts of data transmission and energy consumption of mobile units to select a suitable join query processing scheme based on accurate cost estimate of operations. A cost estimate method for join query processing was presented after a new asymmetrical feature of energy consumption at a mobile unit was exploited. The costs of join query processing schemes were evaluated from data transmission and energy consumption, and the performances of them were comparatively analyzed. Then four practical criteria were achieved to guide us to select the suitable processing scheme and minimize the cost of join operation. The experiments fully demonstrate that the estimate method and the criteria are reliable, and more applicable compared with the existing similar models and results.

Line oriented clustering algorithm based on density

2007, 27(11): 2760-2762.

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After analyzing the deficiencies of the traditional clustering algorithm DBSCAN (Density Based Spatial Clustering of Applications with Noise), a line oriented clustering method based on DBSCAN was proposed. The object clustered changed from the point to the line. The characteristics of line oriented clustering method were studied based on the point oriented clustering method. The algorithm can deal with irregular line sets and find out clusters with different densities. It is proved to be workable and validated by a test.

Application of ant colony system to materialized views selection

2007, 27(11): 2763-2765.

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Ant Colony System (ACS) method was adopted to solve the problem of materialized view selection under a storage space constraint. The pheromone was updated locally and globally, and the optimization solution of each iteration was locally searched, and finally a reasonable solution was got. Compared with genetic algorithm, the simulation results of ACS show its superiority.

Curvature-based registration algorithm of point clouds data

2007, 27(11): 2766-2769.

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A 3-D measuring data registration algorithm was proposed in order to locate the different-view-measured cloud data without clear corresponding relation. In the algorithm, a local parabolic surface was fitted to each neighbor point. The curvature of each point was estimated according to the point and its neighbor points, using Hausdorff distance as measurement criterion. Thus a nominal correspondence was created between the control point set selected from the different positions in the overlapped view area. Then the rotation matrix and translation vector were deduced by quaternion method. The corresponding point sets were judged according to the characteristics of curvature, and the problem of combining arbitrary multiview point clouds was solved. Experimental results show the accurate and robust performance of the proposed algorithm.

Decision trees for accelerating rendering model

Su-Jing MA

2007, 27(11): 2770-2772.

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In order to increase the speed of rendering model, a new accelerating algorithm was proposed, which used the decision tree to classify the segmented voxels into categories and used the runlength encoding (RLE) to memorize the categories. Whenever the voxel model was traversed, only the selected categories were visited and the empty and nonselected voxels were skipped. The results show that the voxel model not only preserves the quality of the images but also significantly accelerates the volume rendering.

3D visualization of electromagnetic field based on visualization toolkit

He XIAO Ming-Yun He Zhonf-Jian BAI Yuan-Yuan ZHOU

2007, 27(11): 2773-2775.

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A thorough discussion on the technological process and the datasets was made, concerning the electromagnetism data multiplicity and data mapping multiplicity in 3D visualization of electromagnetic field. Then, making use of the Visualization ToolKit (VTK) with many builtin algorithms for scalar, vector visualization in computer graphics, the Marching Cube and Hedgehog modeling methods were used to realize the reconstruction for 3D scalar and vector visualization of electromagnetic field.

New connected component labeling algorithm for binary image

2007, 27(11): 2776-2777.

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A new algorithm based on linelabeling and regiongrowing was proposed for binary connected component labeling. All the connected components were labeled with one pass, and had no label collisions. The algorithm was independent of the shapes of the connected regions. Then the new algorithm was optimized and the search time was reduced. The comparative experiments with traditional algorithms show that this new method is more efficient and effective.

Update strategy based on filtering residual image for motion compensation temporal filtering

Hong-Mei Wang Zheng Zhao Yong-Hua Zhang

2007, 27(11): 2778-2780.

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Currently, the most recognized framework for scalable video coding is based on Motion Compensation Temporal Filtering (MCTF). Some improvements on deblocking filter and update step for MCTF were proposed. During the update process, the constraint was requested that the pixels of the update block had the uniform prediction motion vector. Before update process, filtering residual image was performed in both edge and sample dot. The highpassed frames were deblocked to bring about less block artifacts into the lowpass frames, and better reference frames for the following motion compensation. In the mean time, the deblock of the highpassed frames could also improve the coding efficiency for the lowactivated video sequences. Experimental results show that the coding efficiency of the lowpass frames and the subject quality of frames are improved.

Video mosaic algorithm for compressed video

Zhao Bin

2007, 27(11): 2781-2785.

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A video mosaic method was proposed. Firstly, phase correlation was used to roughly compute the translation offset between the first corresponding frames of two video streams, so corner match procedure was speeded up and matching stability was improved. Secondly, in the overlapped region, SIFT method was used to detect and register corners. Then, RANSAC algorithm was used to eliminate outliers to ensure effectiveness of the matched corner pairs. Singular Value DecompositionLeast Square (SVDLS) method and LevenbergMarquardt optimization were used to robustly determine the 8 parameters transform model. For the other frames, global motion vector between consecutive frames was calculated from motion vectors included in compressed video data and projection matrix was obtained between two frames from the projection matrix of the previous frame and global motion of each input video sequence. At the last of the algorithm, a multiband blending technique was adopted to generate the final panorama. Invalid parameters were verified by the translation offset to make LevenbergMarquardt optimization more successful. The experiments show that the proposed algorithm exceeds existing ones in terms of matching speed and stability.

Mosaic algorithm of video sequence

San-Hua Guo Xian-Yong Fang

2007, 27(11): 2786-2788.

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A mosaic algorithm of video sequence was proposed. Firstly, the key frames were extracted from the video sequence. Then, the features detected between adjacent key frames were guided and matched by motion displacement, which was calculated by the optical flow field. With the RANSAC (RANdom SAmpling Consensus) robust estimation and cascade of homography matrix, the homography matrix of the adjacent key frame and the nonadjacent key frame was got. Finally, the seamless mosaic was rendered by image blending. The experiment demonstrates this algorithm is effective.

Automatic stitching approach of aerial image sequence based on SIFT features

Chao GAO Xin ZHANG Yun-Li WANG Hui WANG

2007, 27(11): 2789-2792.

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A new approach for automatic stitching of aerial image sequence was proposed, based on the SIFT (Scale Invariant Feature Transform) features. It consisted of two core steps: image registration and mosaic. The variations between two consecutive frames in aerial sequence are always very notable, thus the present commonlyused featurebased methods are not very suitable for their registration. Concerning this, an iterative registration method using the SIFT features was put forward. Moreover, for image mosaic, a new color fusion method was proposed to achieve smooth stitching results based on human visual features. Finally, experiments on real aerial sequences prove the effectiveness of the proposed stitching approach.

Face recognition with single training sample per person based on generalized slide window and 2DLDA

Cai-Kou CHEN Jian-Ping HUANG Yong-Jun LIU

2007, 27(11): 2793-2796.

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For face recognition with single training sample per person, the conventional face recognition methods which work with many training samples do not function well. Especially, a number of methods based on Fisher linear discrimination criterion can not work because the within-class scatter matrix is a matrix with all elements being zero. To solve this problem, a new sample augment method, called generalized slide window, was proposed. In order to effectively maintain and strengthen the within-class and between-class information, the rule, "big window, small step", was adopted to produce a set of window images for each training image. Then, twodimensional Fisher linear discrimination analysis was performed on the window images obtained. The experimental results on ORL face database confirm that the proposed method is feasible and effective in face recognition with single training sample per person.

Expression feature extraction based on PSO and ICA

2007, 27(11): 2797-2799.

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A combined method of expression feature extraction was proposed based on particle swarm optimization (PSO) and independent component analysis (ICA). Firstly, the basic ICA algorithm was used to build a solving frame of the independent base vector derived from expression images. Secondly, the PSO algorithm was applied to process expression data to get the optimal solution in order to decrease the computing complexity. Finally, Support Vector Machine (SVM) was used to validate the correctness of algorithm. The experiments in the expression database show that it is a faster way of extracting expression features without sacrificing the expression recognition precision.

Stereo matching on uncalibrated images based on epipolar geometry

Lu-Lu JIANG

2007, 27(11): 2800-2803.

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Stereo matching is a key issue in the area of computer vision, and the core issue of the 3D reconstruction of computer as well. It plays a very important role in feature matching and is independent of scene structure. Combining feature matching with epipolar geometry, a robust matching algorithm was carried out on uncalibrated images. The least epipolar distance theory was applied to the fundamental matrix estimate and guided match. The results of the experiments on real images show that this algorithm has better practicality.

Application of an improved adaptive directional median filter in image preprocessing of plastic products

Fuli WANG Yuqing CHANG Yang LIU

2007, 27(11): 2804-2807.

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The disadvantages of the adaptive directional median filters in image preprocessing of plastic product were analyzed. Then considering the requirements of image preprocessing of plastic product, an improved adaptive directional median filter was proposed. The new filter arranged filtering algorithm for each pixel according to their different properties confirmed by the noise detecting algorithm and region detecting algorithm adopted in this filter. Owing to this new strategy, not only the noise in the image is efficiently suppressed, but also better detail preserving ability and shorter CPU time are obtained. The experiments also demonstrate the effectiveness and practicality of this new filter.

Research of hierarchy online learning model and learning control

2007, 27(11): 2808-2811.

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One of the key issues to improve student learning efficiency is to find the integrated learning model and learning control mechanisms, since there are diverse learning needs and lack of learning content in the network environment. The hierarchy learning model of three layers was put forward based on the knowledge space theory and advanced Petri net. The model can get adapted to different learning requirements for different learners with different levels using the same learning content. To a large extent, the model can meet the above needs and avoid the problems of "knowledge lost" and "learning lost". Thus the personalized instruction for learners can be achieved.

Feature selection method based on Fisher criterion and feature clustering

Sa Wang Lian Zheng

2007, 27(11): 2812-2813.

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Feature selection is one of the important issues in the machine learning and pattern recognition. For highdimensional data, the new feature selection method based on Fisher criterion and feature clustering was proposed. Firstly, the features that have more discrimination information based on Fisher criterion were selected. Then hierarchical clustering in the preselected subset was adopted. Finally the irrelevant and redundant features were removed. The experimental results show that the proposed algorithm is an effective method for feature selection.

Comparative study of intuitionistic fuzzy inference and normal fuzzy inference

2007, 27(11): 2814-2816.

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Intuitionistic fuzzy inference overcomes the limitation of normal fuzzy inference such as the problem of describing fuzzy information and the creditability of inference results. Based on the introduction of intuitionistic extensions of normal fuzzy inference, the transformation of two inference algorithms were analyzed, which indicated that fuzzy inference was an example of intuitionistic fuzzy inference, and the two methods could transform when intuitionistic index was zero. Then, reductivity analyses showed that Zadeh, Mamdani and Larsen intuitionistic fuzzy inferences had the same reductivity as the corresponding fuzzy inference algorithm. Finally, the performance study by experiment shows that intuitionistic fuzzy inference is more applicable in intelligence control and decisionmaking than normal fuzzy inference.

Multi-objective optimization algorithm based on the combination of NSGA-Ⅱ and MOPSO

Jin-Hua WANG Ze-Yong Yin

2007, 27(11): 2817-2830.

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A new algorithm was developed through replacing the crossover operation in NSGA-Ⅱ with the mode of position updating in multiobjective particle swarm optimizer (MOPSO). In order to seamlessly combine NSGAⅡand the greatly different MOPSO, the special concepts (particle and its velocity, Pbest and leader) for MOPSO were dealt with within the scope of NSGA-Ⅱ: 1) particle in MOPSO was considered to be equivalent to offspring individual in NSGA-Ⅱ; 2) the concept of velocity fell into disuse; 3) the concept of Pbest also came into disuse. Instead of that, for each dimension of a particle, the nearest one among its nondominated individuals in parent population was used; 4) the leader of a particle was the individual with largest sparse degree among parent population or selected from parent population by binary tournament selection method, which of them taking effect lies on the predefined probability. In addition, a new concept, i.e., sparse degree, was introduced to evaluate the distribution of particles in objective function space. Experiments on six benchmark problems indicate that the new algorithm is an effective and stable one when compared with NSGA-Ⅱ and two of the latest MOPSOs (CLMOPSO and EM-MOPSO).

Fuzzy support vector machine algorithm with dual membership

Ying Huang

2007, 27(11): 2821-2824.

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Based on traditional fuzzy support vector machine (FSVM), a new fuzzy support vector machine, dual membership fuzzy support vector machine (DM-FSVM), was presented. There is only one membership in traditional support vector machine (SVM) model; however, there are two memberships in DMFSVM. This method not only keeps the advantages of traditional FSVM, but also makes full use of limited data and improves the classification efficiencies. Experiments show that DMFSVM improves the classification accuracy.

Particle swarm collaborative optimization algorithm based on velocity angle

2007, 27(11): 2824-2825.

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Particle swarm optimization (PSO) algorithm is a stochastic global optimization technique, and it has been successfully applied in many areas. Concerning the disadvantage of the original PSO that is easily trapped in the local optimization and the convergence speed is slow in the evolution later, a particle swarm collaborative optimization algorithm based on velocity angle (V-PSCO) was proposed. The strategy of inertia weight adjustment was adopted based on cumulative distribution function of Gaussian distribution. V-PSCO was used to resolve several widely used test function optimization problems. Results show that V-PSCO has better ability of global search and can effectively improve the performance.

Strategy for improving the performance of chained Lin-Kernighan algorithm

Dong WANG

2007, 27(11): 2826-2829.

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Lin-Kernighan algorithm is a kind of high effective optimization algorithm for combinatorial optimization problems. Traveling Salesmen Problem (TSP) is one of the typical NPhard problems in the field of combinatorial optimization. Through the discussion on the simplification of the problems, probability simplifying model was established, the prior probability was produced via experimental analysis, and stochastic algorithm for simplifying initial edge set of traveling salesman problem was constituted. The solving performance of chained Lin-Kernighan algorithm was improved obviously by utilizing the edge set produced by the stochastic algorithm as reference optimizing edge set of chained LinKernighan algorithm. Better convergence effect was achieved while combining the stochastic algorithm with different intelligence algorithms.

Genetic algorithm for mobile Agent tasks scheduling

Ai-zhen LIU Jia-zhen WANG

2007, 27(11): 2830-2833.

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A chaos genetic algorithm was proposed to search the optimal solution in the whole feasible solution space. The problem model and chromosome representation were defined. The initial population was generated by the greedy algorithm, in which the communication cost was taken into account. To make the new scheduling generated by crossover mechanism valid, a new crossover mechanism was presented. The heuristic mutation operator was adopted. The chaos theory was used to dynamically control crossover and mutation operation. And the parent best chromosomes preserving strategy was adopted. Finally 18 task graphs simulation results on three kinds of communicationtocomputation ratio, two kinds of task number and three kinds of host nodes were given.

Hybrid high performance model of computer algebra system

2007, 27(11): 2834-2837.

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Computer Algebra System (CAS) is a vital backbone in the field of symbolic computation and automated reasoning. There are many excellent CASs, which can provide good interface and quick computation for researchers. However, they are only designed to work on some special purposes, i.e., polynomial operations or calculation of Groebner basis, which lead to inefficient collaboration. A hybrid high performance model of computer algebra system (HHPCAS) was outlined. HHPCAS provided high performance by expanding the kernel library in CAS, using external calling and integrating the parallel library and cluster management software. Each job was submitted to a queue and scheduled by its ticket and slot value, which denoted the priority of job. In HHPCAS, several examples were tested by implementing an algorithm named parallel successive difference substitution. The experimental result shows that HHPCAS is effective for complex problem in symbolic computation and automated reasoning.

Testing the memory allocation performance of real-time operating system

2007, 27(11): 2838-2840.

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This article discussed the method of testing the performance of RTOS' memory allocation. It produced memory debris by utilizing the method of probability and statistics. Under the different conditions, it detected the changes of the RTOS' memory allocation. The performance of VxWorks' memory allocation was tested by using the memory debris which was produced by the normal random number. At last, its performance was analyzed based on the testing data. These data showed that the VxWorks was consistent with the requirements of RTOS. And it also validated the feasibility and credibility of this testing method.

Research and design of resources competing mechanism of hardware/software tasks based on unified scheduling

2007, 27(11): 2841-2843.

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Oriented to RTOS (Real-Time Operating System) in SOPC (System-On-Programmable-Chip), a unified scheduling model was built based on hardware/software unified multi-task management model. Then, competition for the shared resources between hardware/software tasks was analyzed, a deep research was made into its internal operational mechanism, and a SHTRCR (Software/Hardware Tasks Resources Competition Resolution) method was designed to address the resources competing problem between hardware/software tasks based on the recording semaphore mechanism and unified scheduling model. Simulation experiments show that under the same conditions, SHTRCR achieves higher deadlineguarantee ratio than other methods without the support of unified scheduling model.

Architecture of cluster-based streaming caching proxy server

2007, 27(11): 2844-2846.

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The architecture of the cluster-based streaming caching proxy server was proposed, and content-aware scheduling mechanism was adopted to improve the performance of the scheduling in the cluster. In addition, the designing principle as well as the modules and the communication mechanism among them were addressed in detail. The system was implemented under Linux platform by C and C++ language and tested through simulation testing method. From the testing results, it can be confirmed that the whole system is well designed which achieves high performance, good robustness and high scalability.

Survey on network-on-chip topology

2007, 27(11): 2847-2850.

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A survey on main research topics in the area of Network-on-Chip (NoC) topology was introduced. The classification of NoC topology was given, and each specific topology was discussed in detail. From the point of view of network topology, several NoC case studies were conducted, and then related NoC design works were summarized. In the end, some future research directions of NoC topology were presented.

Cache policy based bytecode verification on Java card

2007, 27(11): 2851-2853.

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As an unreliable application, Java card bytecode verification is an indispensable part for a secure embedded system. For the limited space and time of Java card itself, the conventional bytecode verification is not able to use. To address this feasibility problem, the nonvolatile memory was used as the main memory and part of the RAM as the cache, and a modified verification algorithm with cache policy was proposed. The analysis proved that this algorithm features strong transportability and feasibility.

Detection and elimination of similar Web pages based on text structure

Li-Xia WEI jia-heng zheng

2007, 27(11): 2854-2856.

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Similar Web pages that search engine returns not only waste storage resources but also increase the burden on Web users. A dynamic method to detect similar Web pages was proposed. By this method, Texts of Web pages were expressed in the style of catalogue structure trees according to the features of similar Web pages and the features of Web pages themselves. A dynamic algorithm to extract features of texts and a layer fingerprint algorithm to calculate similar degree were implemented. The experimental results show that completely similar Web pages are detected accurately, and partly similar Web pages are detected exactly.

Design and implementation of adaptive best-first Web spider

WEI Wen-guo XIE Gui-yuan

2007, 27(11): 2857-2859.

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NonHogSearch, a topic-specific search engine based on improved bestfirst search algorithm was designed and implemented, which decreased the searching greed degree. Signal-to-noise ratio of Web page was used to judge whether or not the page belonged to the search topic. Further NonHogSearch Web spider made online-incremental adaptive learning, the reward generated directly by the ontopic pages would be feedback along the link-chain to update all the value Q of the links. NonHogSearch avoids going into local best solutions space earlier, and the performance of Web spider was improved. Experiments prove that it has better recall rate and precision rate than others.

Application of multiclass SVM based on binary tree in E-mail filtering

2007, 27(11): 2860-2862.

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Now some preferable performance multiclass algorithms, such as 1-v-r support vector machine (SVM) , 1-1-1 SVM and DDAG SVM，have many problems of impartible regions and longer training time.A new multiclass SVM algorithm based on binary tree was introduced on E-mail filtering. It could convert multiclass problem to binary classification by constructing binary tree. The idea of clustering first and classification later was adopted, and the largest similarity between testing sample and sub-category center and the separation measure of subcategories were calculated, in oder to construct the optimal class hyperplane of decisionmaking nodes. Only C-1 optimal functions were needed for C kinds of classification, so training time could be saved. The experiment results show that the new algorithm has higher filtering recall and precision.

Personalization recommendation based on customer's behavior under DMA-based sequential pattern

Chen-Chen LIU

2007, 27(11): 2863-2865.

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The E-commerce leads to the moreintensive competition among the entities, and personalization recommendation would be the breakthrough to increase the customer's loyalty and promote the profits. The dynamic mining algorithm was proposed and improved to realize the personalization recommendation based on customers purchase sequences. The definition of time contraint was put forward considering the impact of the length of the times compartmentalization and the selflearning function of the system was realized. The result of an imitating experiment indicates that the recommendation method proposed is feasible and effctive.

Loose coupling algorithm for biomedical named entity recognition

Jun-Feng HU

2007, 27(11): 2866-2869.

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The rapid development of biology and medicine in recent years leads to speedy accumulation of gigabyte biomedical information. How to use technical methods to mine and utilize the information becomes more and more important. Biomedical Named Entity Recognition (Bio-NER) is a basal work for mining and utilizing biomedical literatures. Concerning the difficulties and problems of the existing Bio-NER algorithms, a loose coupling algorithm named LCA for Bio-NER was proposed. The biomedical named entities were recognized based on heuristic rule filter, POS pattern matching pattern matching and modified Hidden Markov Model (HMM) approaches. The experimental results on GENIA corpus 3.02 show that the precision and recall of LCA are around 80% and 89% respectively, higher than the results of the related works.

Weed recognition method based on color and morphological features in wheat field

Wei-Xing ZHU Fei-Jian JIN Rong-Rong TAN

2007, 27(11): 2870-2872.

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The technology of weed recognition based on machine vision becomes a hot issue of precision agriculture. Concerning the severe occluding of leaves of weed and wheat, a weed identification method was proposed with color and morphological features. Color feature was utilized to distinguish plants and background: a* was taken as characteristic variant in L*a*b* color space, and the improved method of maximum classes square error was taken as the criterion; Color feature was utilized to distinguish wheat and weed: hierarchical approach was used to color image segmentation in HSI color space; Morphological feature was utilized to obtain weed: using morphological opening and closing filter, and AND operation algorithm. The proposed methods together with a chemical weeding system were simulated and the efficiency of the overall system was evaluated theoretically. The experimental results on a series of weed images show that the correct identification rate exceeds 92.6%, and the herbicide reduction rate exceeds 72.4%.

Interactive timetabling approach based on greedy method and tabu search

Wei WANG LiHua YU

2007, 27(11): 2873-2876.

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University timetabling is a widely used NP hard optimization problem, hence finding a high quality timetable is a challenging work. The hard and soft constraints of university timetabling problem were analyzed, and then an interactive timetabling system based on greedy method and tabu search was proposed. Greedy method was used to construct an initial solution at the first phase and tabu search was used to find an optimal timetable at the second phase. The prototype is implemented and the experimental results show that the approach is both practical and efficient.

Improved binary search anti-collision algorithm in RFID system

2007, 27(11): 2877-2879.

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Collision is a familiar problem in a Radio Frequency IDentification (RFID) system. How to solve this problem effectively is very vital to the whole RFID system. Binary search algorithm including anti-collision algorithm based on jumping and dynamic searching is a very important anticollision algorithm to solve the collision problems. But the main disadvantage of any existing algorithm based on binary search algorithm is the rate of identifying the identification codes (IDs) of tags is low. In this paper, an improved anti-collision algorithm was proposed in order to solve this problem. By using this algorithm the number of request commands can be reduced greatly, meanwhile the message handling capacity can be improved. Simulation results show that an improvement of 29.85 percent can be achieved through this algorithm when the number of tags is 100.

Application of RBF-ARX model to three-tank water level control system

Qiu-Lian DENG

2007, 27(11): 2880-2884.

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Three-tank water level system was modeled by using RBF-ARX model. The design of the structure of RBF-ARX model, model parameter identification, and radical basis function (RBF) parameters optimization were discussed particularly. Compared with the ARX model in 1-step predictive control, the results show the superiority of the RBF-ARX model in the modeling of nonlinear systems.

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